1. Field of the Invention
The present invention relates to an image transfer sheet and an image forming method therefor in which an image is formed on the image transfer sheet by an image recording method, such as electrophotography, thermal transfer recording, ink jet recording or the like and the formed image on the image transfer sheet is transferred onto an image receiving material, such as cloth, canvas, plastics, paper, wood, leather, glass, china, metals or the like.
2. Discussion of the Related Art
Recently, a variety of image forming apparatus have been developed and utilized for copiers and printers for computers or the like. The images formed with these image forming apparatus are not only used for a purpose of reading or viewing, but also tried to be applied for various new applications.
As one of these new applications of the images, a method is proposed in which the images are transferred onto an image receiving material, such as cloth, canvas, plastics, paper, wood, leather, glass, china, metals or the like. This method is useful for manufacturing a small lot of made-to-order goods having original pictures thereon, such as T-shirts, sweat shirts, aprons, jackets, cups, plates or stained glass and for duplicating of pictures on canvas. Currently, since full color copiers are developed and high quality full color images can easily be obtained, the demand for this method is increasing more and more.
Such an image transfer sheet that transfers toner images thereon onto an above-mentioned image receiving material is discussed in Japanese Laid-Open Patent Application No. 52-82509, incorporated herein by this reference. In the patent application, an image transfer sheet is disclosed in which an adhesive layer including an adhesive material selected from the group consisting of silicone and fluorine-containing polymers is formed on a substrate and an image transfer layer including a specific polymer having a relatively low melting point is formed on the adhesive layer. Toner images are formed on the image transfer layer and the formed toner images are then transferred onto an image receiving material together with the image transfer layer which is softened when heated to transfer the toner images. The specific examples of the polymer having a relatively low melting point which are described for use in the image transfer layer of the patent application are the polymers selected from the group consisting of polyvinyl chloride, polyvinyl acetate, polymethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate and polyvinylidene chloride and the mixtures and the copolymers thereof. However, the adhesion of these polymers to the above-mentioned image receiving materials is insufficient, so that a problem occurs in which transferred images on the image receiving materials are easily peeled from the image receiving materials after several times of washing. In addition, a problem also occurs in which transferred images are destroyed or adhered to an iron when the image receiving material bearing transferred images is ironed. This is because the transferred images are melted or softened by the heat of the iron.
Because of these reasons, a need exists for an image transfer sheet which has good image receivability when an image is formed on the image transfer sheet and good image transferability and fixability when the image is transferred onto various receiving materials.